一本教会你“做对”题的6级阅读书 day6 passage2

[00:02]Medibots : The world's smallest surgeons [00:06]A man lies unconscious on an operating table. [00:10]The enormous spider that hangs above him [00:13]has plunged four apparatus into his belly. The spider, made of white steel, [00:20]probes around inside the man's abdomen then withdraws one of its arms. [00:25]Held in the machine's claw is a neatly sealed bag [00:29]containing a scrap of bloody tissue. [00:32]This is a da Vinci robot. It has allowed a surgeon, [00:37]sitting at a control desk, to remove the patient's gland in a manner [00:42]that has several advantages over conventional methods. [00:45]Yet the future of robotic surgery may lie not only [00:49]with these large beasts but also with devices at the other end of [00:54]the size spectrum. The surgeons of tomorrow will include tiny robots [01:00]that enter humans' bodies and do their work from the inside, [01:04]with no need to open patients up or knock them out. [01:09]While tiny robots that swim through the blood [01:12]are still in the realm of fantasy, several groups are developing devices [01:17]a few millimetres in size. The first generation of "mini-medibots" [01:23]may enter our bodies through our ears, eyes and lungs, to deliver drugs, [01:28]take tissue samples or install medical devices. [01:33]The engineering challenges are great, [01:35]including developing new methods of driving force and power supply. [01:40]Nevertheless, the first prototypes are already being tested in animals [01:46]and could move into tests on people in the not-too-distant future. [01:51]"It's not impossible to think of this happening in five years," says Brad Nelson, [01:57]a roboticist at the Swiss Federal Institute of Technology in Zurich. [02:03]"I'm convinced it's going to get there." [02:06]It was the 1970s that saw the arrival of minimally invasive surgery [02:12]or keyhole surgery as it is also known. Instead of cutting open the body [02:17]with large cuts, surgical tools are inserted through holes as small as [02:23]1 centimetre in diameter and controlled with external handles. [02:28]Some operations are now done this way, reducing blood loss, [02:32]pain and recovery time. [02:36]Combining keyhole surgery with the da Vinci system [02:40]means the surgeon no longer handles the instruments directly, [02:44]but via a computer control panel. This allows greater precision, [02:49]as large hand gestures can be scaled down to small instrument movements, [02:55]and any hand tremor is eliminated. [02:57]There are over 1000 da Vincis being used in clinics around the world. [03:04]Heart crawler [03:06]There are several ways that such robotic surgery may be further enhanced. [03:12]Various jointed, snake-like tools [03:15]are being developed to access hard-to-reach areas. One such device, [03:21]the "i-Snake", is controlled by a vision-tracking device [03:25]worn over the surgeon's eyes. [03:28]It should be ready for testing on patients within four years, [03:32]says developer Guang-Zhong Yang, a roboticist at Imperial College London. [03:38]With further advances in miniaturisation, [03:41]the opportunities grow for getting medical devices [03:45]inside the body in novel ways. One miniature device [03:49]that is already tried and tested is a camera in a capsule [03:54]small enough to be swallowed. [03:58]In conventional test, a camera on the end of a flexible tube [04:02]is inserted through the mouth, [04:04]but this does not allow it to reach the middle part of the gut. [04:09]The 25-millimetre-long capsule camera, on the other hand, [04:13]can observe the entire gut on its journey. [04:17]More sophisticated versions are being developed [04:20]that can also release drugs and take samples. [04:25]The capsule camera has no need to propel itself [04:28]because it is pushed along by the normal muscle contractions of the gut. [04:34]For devices used elsewhere in the body, [04:37]some scientists are developing new mechanisms for driving force [04:42]and power supply on a miniature scale. [04:46]One solution is to have wires connecting the robot to a control unit [04:51]that remains on the outside of the body. [04:54]This is the case for a robot being developed for heart surgery, [04:58]called HeartLander. [05:01]Operating on the heart has always presented enormous challenges, [05:05]says Marco Zenati, a heart surgeon at the University of Pittsburgh, [05:10]Pennsylvania, who is one of the device's inventors. [05:14]Conventionally the heart is stopped [05:16]and the patient hooked up to a heart-lung machine. [05:20]A more recent approach is to perform keyhole surgery on the beating heart, [05:26]but even so several cuts must be made, [05:29]and the left lung must be partly deflated to allow access. [05:34]The HeartLander robot is designed to be delivered to the heart [05:38]through a single keyhole cut, from where it can crawl to the right. [05:43]The 20-millimetre-long HeartLander has front and rear foot-pads [05:48]with suckers on the bottom, which allow it to move along like a worm. [05:53]The surgeon watches the device with X-ray video or a magnetic tracker [05:58]and controls it with a control stick. Alternatively, [06:03]the device can navigate its own path to a spot chosen by the surgeon. [06:08]The HeartLander has several possible uses. [06:11]It can be fitted with a needle attachment to take tissue samples, [06:16]for example, or used to inject stem cells [06:20]or gene therapies directly into heart muscle. [06:24]There are several such agents in development, [06:27]designed to promote the regrowth of muscle or blood vessels [06:31]after a heart attack. The team is testing the device on pigs [06:36]and has so far shown [06:38]that it can crawl over a beating heart to inject a marker dye at a target site. [06:46]Another use would be to deliver pacemaker electrodes for a procedure, [06:51]when the heart needs help in coordinating its rhythm. [06:56]At the moment, the electrodes are delivered to the heart [06:59]by pushing them in through a vein. Riviere's group [07:03]is devising electrodes that the HeartLander [07:06]could attach to the outer surface of the heart. [07:10]They have tested this approach successfully on one live pig, [07:15]and expect to start trials in people in about four years. [07:19]Riviere says there is growing evidence to show that the technique works best [07:25]when the electrodes are sited in certain areas [07:28]that are hard to access from inside the veins. [07:32]"The HeartLander can crawl around to the best position," he notes. [07:38]While the robot could in theory be used in other parts of the body, [07:43]in its current incarnation it has to be introduced [07:46]through a keyhole incision thanks to its size and [07:50]because it trails wires to the external control box. [07:54]Not so for smaller robots under wireless control. [07:59]One such device in development is 5 millimetres long [08:04]and just 1 millimetre in diameter, with 16 vibrating legs. [08:10]Early versions of the "ViRob" had on-board power, [08:15]but the developers decided that made it too bulky. [08:19]Now it is powered externally, by a nearby electromagnet [08:23]whose field fluctuates about 100 times a second, [08:28]causing the legs to flick back and forth. [08:32]The legs on the left and right sides respond best to different frequencies, [08:37]so the robot can be steered by adjusting the frequency. [08:41]ViRob's developers at the Technion-Israel Institute of Technology in Haifa, [08:47]are investigating several applications including taking tissue samples, [08:51]delivering cancer drugs and getting a camera to hard-to-reach areas, [08:57]such as deep within the lungs. The size of the camera is a limiting factor [09:02]the smallest models in development are 1.5 millimetres in diameter [09:07]but cameras get smaller every year, notes engineer Moshe Shoham. [09:13]The team would like their device to operate inside large blood vessels, [09:19]but it is not yet powerful enough to withstand blood flow. [09:23]"We don't want it swept away," says Shoham. [09:27]One application for ViRob may benefit people born with fluid on the brain [09:33]as it may be able to extend the life of the shunts placed [09:37]in the brain to drain the excess fluid. [09:40]Over time such shunts tend to get blocked, [09:44]and so need replacing every five to 10 years, [09:48]entailing major brain surgery. Shoham says a self-cleaning shunt [09:53]could be made by installing a ViRob permanently inside. [09:58]In fact, if millimetre-sized devices prove their worth, [10:03]they will attract more funding to kick-start the research. [10:07]Small devices that do something useful will convince people [10:11]that it's not just science fiction.

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Passage 2 Medibots: The World’s Smallest Surgeons 105
世界上最小的外科医生 《新科学家》

[00:02]Medibots : The world's smallest surgeons
[00:06]A man lies unconscious on an operating table.
[00:10]The enormous spider that hangs above him
[00:13]has plunged four apparatus into his belly. The spider, made of white steel,
[00:20]probes around inside the man's abdomen then withdraws one of its arms.
[00:25]Held in the machine's claw is a neatly sealed bag
[00:29]containing a scrap of bloody tissue.
[00:32]This is a da Vinci robot. It has allowed a surgeon,
[00:37]sitting at a control desk, to remove the patient's gland in a manner
[00:42]that has several advantages over conventional methods.
[00:45]Yet the future of robotic surgery may lie not only
[00:49]with these large beasts but also with devices at the other end of
[00:54]the size spectrum. The surgeons of tomorrow will include tiny robots
[01:00]that enter humans' bodies and do their work from the inside,
[01:04]with no need to open patients up or knock them out.
[01:09]While tiny robots that swim through the blood
[01:12]are still in the realm of fantasy, several groups are developing devices
[01:17]a few millimetres in size. The first generation of "mini-medibots"
[01:23]may enter our bodies through our ears, eyes and lungs, to deliver drugs,
[01:28]take tissue samples or install medical devices.
[01:33]The engineering challenges are great,
[01:35]including developing new methods of driving force and power supply.
[01:40]Nevertheless, the first prototypes are already being tested in animals
[01:46]and could move into tests on people in the not-too-distant future.
[01:51]"It's not impossible to think of this happening in five years," says Brad Nelson,
[01:57]a roboticist at the Swiss Federal Institute of Technology in Zurich.
[02:03]"I'm convinced it's going to get there."
[02:06]It was the 1970s that saw the arrival of minimally invasive surgery
[02:12]or keyhole surgery as it is also known. Instead of cutting open the body
[02:17]with large cuts, surgical tools are inserted through holes as small as
[02:23]1 centimetre in diameter and controlled with external handles.
[02:28]Some operations are now done this way, reducing blood loss,
[02:32]pain and recovery time.
[02:36]Combining keyhole surgery with the da Vinci system
[02:40]means the surgeon no longer handles the instruments directly,
[02:44]but via a computer control panel. This allows greater precision,
[02:49]as large hand gestures can be scaled down to small instrument movements,
[02:55]and any hand tremor is eliminated.
[02:57]There are over 1000 da Vincis being used in clinics around the world.
[03:04]Heart crawler
[03:06]There are several ways that such robotic surgery may be further enhanced.
[03:12]Various jointed, snake-like tools
[03:15]are being developed to access hard-to-reach areas. One such device,
[03:21]the "i-Snake", is controlled by a vision-tracking device
[03:25]worn over the surgeon's eyes.
[03:28]It should be ready for testing on patients within four years,
[03:32]says developer Guang-Zhong Yang, a roboticist at Imperial College London.
[03:38]With further advances in miniaturisation,
[03:41]the opportunities grow for getting medical devices
[03:45]inside the body in novel ways. One miniature device
[03:49]that is already tried and tested is a camera in a capsule
[03:54]small enough to be swallowed.
[03:58]In conventional test, a camera on the end of a flexible tube
[04:02]is inserted through the mouth,
[04:04]but this does not allow it to reach the middle part of the gut.
[04:09]The 25-millimetre-long capsule camera, on the other hand,
[04:13]can observe the entire gut on its journey.
[04:17]More sophisticated versions are being developed
[04:20]that can also release drugs and take samples.
[04:25]The capsule camera has no need to propel itself
[04:28]because it is pushed along by the normal muscle contractions of the gut.
[04:34]For devices used elsewhere in the body,
[04:37]some scientists are developing new mechanisms for driving force
[04:42]and power supply on a miniature scale.
[04:46]One solution is to have wires connecting the robot to a control unit
[04:51]that remains on the outside of the body.
[04:54]This is the case for a robot being developed for heart surgery,
[04:58]called HeartLander.
[05:01]Operating on the heart has always presented enormous challenges,
[05:05]says Marco Zenati, a heart surgeon at the University of Pittsburgh,
[05:10]Pennsylvania, who is one of the device's inventors.
[05:14]Conventionally the heart is stopped
[05:16]and the patient hooked up to a heart-lung machine.
[05:20]A more recent approach is to perform keyhole surgery on the beating heart,
[05:26]but even so several cuts must be made,
[05:29]and the left lung must be partly deflated to allow access.
[05:34]The HeartLander robot is designed to be delivered to the heart
[05:38]through a single keyhole cut, from where it can crawl to the right.
[05:43]The 20-millimetre-long HeartLander has front and rear foot-pads
[05:48]with suckers on the bottom, which allow it to move along like a worm.
[05:53]The surgeon watches the device with X-ray video or a magnetic tracker
[05:58]and controls it with a control stick. Alternatively,
[06:03]the device can navigate its own path to a spot chosen by the surgeon.
[06:08]The HeartLander has several possible uses.
[06:11]It can be fitted with a needle attachment to take tissue samples,
[06:16]for example, or used to inject stem cells
[06:20]or gene therapies directly into heart muscle.
[06:24]There are several such agents in development,
[06:27]designed to promote the regrowth of muscle or blood vessels
[06:31]after a heart attack. The team is testing the device on pigs
[06:36]and has so far shown
[06:38]that it can crawl over a beating heart to inject a marker dye at a target site.
[06:46]Another use would be to deliver pacemaker electrodes for a procedure,
[06:51]when the heart needs help in coordinating its rhythm.
[06:56]At the moment, the electrodes are delivered to the heart
[06:59]by pushing them in through a vein. Riviere's group
[07:03]is devising electrodes that the HeartLander
[07:06]could attach to the outer surface of the heart.
[07:10]They have tested this approach successfully on one live pig,
[07:15]and expect to start trials in people in about four years.
[07:19]Riviere says there is growing evidence to show that the technique works best
[07:25]when the electrodes are sited in certain areas
[07:28]that are hard to access from inside the veins.
[07:32]"The HeartLander can crawl around to the best position," he notes.
[07:38]While the robot could in theory be used in other parts of the body,
[07:43]in its current incarnation it has to be introduced
[07:46]through a keyhole incision thanks to its size and
[07:50]because it trails wires to the external control box.
[07:54]Not so for smaller robots under wireless control.
[07:59]One such device in development is 5 millimetres long
[08:04]and just 1 millimetre in diameter, with 16 vibrating legs.
[08:10]Early versions of the "ViRob" had on-board power,
[08:15]but the developers decided that made it too bulky.
[08:19]Now it is powered externally, by a nearby electromagnet
[08:23]whose field fluctuates about 100 times a second,
[08:28]causing the legs to flick back and forth.
[08:32]The legs on the left and right sides respond best to different frequencies,
[08:37]so the robot can be steered by adjusting the frequency.
[08:41]ViRob's developers at the Technion-Israel Institute of Technology in Haifa,
[08:47]are investigating several applications including taking tissue samples,
[08:51]delivering cancer drugs and getting a camera to hard-to-reach areas,
[08:57]such as deep within the lungs. The size of the camera is a limiting factor
[09:02]the smallest models in development are 1.5 millimetres in diameter
[09:07]but cameras get smaller every year, notes engineer Moshe Shoham.
[09:13]The team would like their device to operate inside large blood vessels,
[09:19]but it is not yet powerful enough to withstand blood flow.
[09:23]"We don't want it swept away," says Shoham.
[09:27]One application for ViRob may benefit people born with fluid on the brain
[09:33]as it may be able to extend the life of the shunts placed
[09:37]in the brain to drain the excess fluid.
[09:40]Over time such shunts tend to get blocked,
[09:44]and so need replacing every five to 10 years,
[09:48]entailing major brain surgery. Shoham says a self-cleaning shunt
[09:53]could be made by installing a ViRob permanently inside.
[09:58]In fact, if millimetre-sized devices prove their worth,
[10:03]they will attract more funding to kick-start the research.
[10:07]Small devices that do something useful will convince people
[10:11]that it's not just science fiction.